


demons are like obedient dogs, they come when they are called

by tianyu



Category: Shingeki no Kyojin | Attack on Titan
Genre: Abusive Relationships, Alternate Universe - Demons, Alternate Universe - Magic, Anal Sex, Blasphemy, Blood Drinking, Demon Levi (Shingeki no Kyojin), Incubus Levi (Shingeki no Kyojin), M/M, Non-Graphic Violence, Stockholm Syndrome, Unhealthy Relationships, i would classify this as a dead dove, so you have been warned
Language: English
Status: Completed
Published: 2020-04-27
Updated: 2020-04-27
Packaged: 2021-03-02 01:01:53
Rating: Mature
Warnings: Rape/Non-Con
Chapters: 1
Words: 3,619
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23876608
Author URL: https://archiveofourown.org/users/tianyu/pseuds/tianyu
Summary: As the legend goes, don’t speak ill of the Commander, or your family will find your decapitated head placed at their doorsteps. Don’t disrespect the Commander, or you’ll find your child’s lifeless body floating along the riverbanks.Most importantly, don’t bring physical harm to the Commander, because his attack dog will make sure that every last person carrying your blood will be slaughtered mercilessly.
Relationships: Krista Lenz | Historia Reiss/Ymir, Levi/Erwin Smith
Comments: 5
Kudos: 49





	demons are like obedient dogs, they come when they are called

**Author's Note:**

> so i decided to write more eruri when i was taking a break from writing my eruri trilogy. 
> 
> eruri is love. eruri is life.

As the legend goes, the Commander of the Royal Military, Erwin Smith, has an attack dog that follows his every command. No one else can keep it tame, yet it always listens to Smith unconditionally. 

Smith’s lapdog, people dub it, Smith’s mad mutt.

Smith’s bitch, some daringly whisper to others, logic flawed and reason inhibited at the local tavern, bet Smith likes to get his dick wet with that little pet of his behind the curtains.

Some will laugh along, others will nervously look away, pretending not to hear the crude accusations. 

Smith is a benevolent, albeit stoic, leader. Temporary, until Her Royal Highness, the Princess grows of age and can successfully inherit and ascend Her throne. Some choose not to badmouth him due to their respect and gratefulness, others keep their mouths shut because of the fear they feel of his attack dog. 

There are legends about that too, but those who don’t know about them don’t speak of them, and those who know, they _know_.

Don’t insult the Commander, some caution, the warnings more frequent the closer they are to the heart of the kingdom, keep your head low and your mouth shut, or else the attack dog will be on your trail. It’ll hunt you down and snap your neck. Won’t let you go until it can scent death rotting off your body.

Those who hear these rumours on the outskirts of the kingdom as the words travel far and wide, think Smith’s attack dog is a bloodthirsty hound. Those who reside in the city catch glimpses of a raven-haired man, who stalks after the Commander like a loyal mutt. 

Levi the soldier, they call him, Levi the attack dog. 

Stronger than any human. Stronger than any beast. Undefeatable. Indestructible. He does not bow down to anyone. He does not kneel for anyone. No one except Erwin Smith, the dog’s chosen master. 

And as with most legends, this one is also wrong. 

There are undeniable elements of truth, though, amusingly. Don’t speak ill of the Commander, or your family will find your decapitated head placed at their doorsteps. Don’t disrespect the Commander, or you’ll find your child’s lifeless body floating along the riverbanks. 

Most of all, don’t bring physical harm to the Commander, because his attack dog will make sure that every last person carrying your blood will be slaughtered mercilessly. Will ensure that your bloodline is destroyed completely. Paint the streets with the blood spilling from their mutilated bodies. 

It is, surprisingly, only the bit about Levi’s loyalty that is incorrect. Away from prying eyes and hushed whispers of gruesome legends, Levi does not comply with Erwin’s requests of him. 

Because Levi is not an attack dog, not a mad mutt, not a soldier nor a bitch. Nor is he human.

He is a demon. Summoned by and bound to Erwin with Magic so ancient that even he cannot sever. He is loyal to Erwin to a fault. As long as Erwin continues to feed him, Levi will let him do his little human things. 

Which are useless. Futile. At the end of the day, Erwin is destined to die by Levi’s hands, soul tied infinitely to Levi even when his body returns to the Earth. He will never be laid to rest, never reach peace and tranquility. This is the price he will pay for desiring access to Levi’s unlimited power. 

And while Levi protects him, it is for his own selfish cause. Erwin can only die by his hands, when Levi decides that his soul is ripe for taking, or otherwise Levi’s efforts will be for naught. He will continue to serve as his loyal dog in front of the eyes of others, but behind closed doors, Erwin must feed him. Must let him satiate his hunger before he brings destruction down onto the human realm, onto Her kingdom. 

The legends don’t speak about these parts. The legends don’t mention the way Levi feeds from Erwin. Of the carnal way Levi takes from Erwin, of the sins committed, hidden behind the heavy locked doors of Erwin’s quarters. Of what Erwin has to do in return for the power he borrows from Levi. 

Everything comes at a price. 

Levi resents the way Erwin’s expression remains undisturbed, even as he plunges his fingers roughly into Erwin’s gaping hole. It refuses to tighten back up now, used and stretched like a cheap whore’s sloppy cunt. It presents itself to Levi, sluttily, begging for more. Levi whispers what he sees into Erwin’s ear, blood mixed with semen pooling in his palm, and preens as the red blush of shame overcomes and rectifies Erwin’s well-crafted neutrality. 

And then Levi feeds. He devours and devours, consumes the humiliation rolling off of Erwin’s body in waves. The spicy, sweet scent of sex is nice and all, but there’s nothing quite as enticing and delectable as Erwin’s embarrassment, enhanced by the awareness of what he’s done, of what he’s allowing to be done, of what he’s willingly letting the demon do to his body for the sake of power. 

Shame is almost always more delicious than pleasure. But most of all, Levi wants to taste Erwin’s regret. 

This comes, packaged in the form of fury, one bright, sunny morning. 

“Levi,” Erwin hisses, summoning the demon to his room, “Undo whatever horrid deed you placed on Her Royal Highness Historia.” 

Levi manifests, sprawled lazily across Erwin’s bed. “There is nothing I can do,” he states, “Your Royal Highness Historia contracted Ymir Herself. It is nothing I did.” 

Erwin lets out a string of curses at that. Levi finds it mildly entertaining, he has never witnessed the Commander so genuinely express such fury and anger before. 

“You promised you would protect her. By all means necessary,” Erwin glares at him. A lesser man would have pissed his trousers at the harsh coldness and the blazing rage Erwin’s currently regarding Levi with. “We made a deal, I allowed you to feed from me for three days straight.” 

“And did I not?” Levi counters, belly warming at the memory of the way Erwin could cough up his cum through his nose at the end of those wonderful three days. “I have prevented all and any physical harm that has come Her way. Slaughtered the countless men and women who had attempted to hurt Her. How do you expect me to prevent Her from bringing harm onto Herself? You are contradicting yourself.”

“She is but a child!” Erwin bellows, “Kill the demon then, free Her. She is the last of the Royal Bloodline, I have promised to keep Her well until Her coronation. You too have promised this duty.”

“I cannot,” Levi says, easily, “Ymir is a powerful demon, The Curse of Ymir is beyond the dimensions I guard. Besides, the Curse is cast in a way so that if Ymir perishes, so will your darling Highness. She is now a Subject of Ymir. She is under Ymir’s protection, no harm will ever come of Her again. You should be glad. She is a smart girl for summoning Ymir and not any other demon.”

“Glad? You have cursed Her, condemned Her,” Erwin accuses, furious, “You must have put the thoughts and influence into Her head.”

Levi assesses him levelly. “No,” he calmly replies, “You did. You planted the seed of an idea in Her mind. You must know that She admires you more than She had with Her own father, She thinks the only way She can do the rightful thing for Her kingdom is to follow in your footsteps, become like you. You have condemned Her to an eternity of torture, my Commander. It is no one’s fault but your own.” 

Erwin grits his teeth and glares at him. “You are supposed to keep Her safe and you have failed.” Levi almost moans at the first hint of the distinct scent of regret seeping into the air surrounding them. Oh, the things he would do to keep the scent fresh and alive at all times. His stomach clenches with hunger pains, he must eat now.

“Do not touch me,” Erwin orders, “I do not want to see you.”

And Levi is forced to manifest away, reigned by the constraints of Magic Erwin holds over him. 

His hunger pierces through his abdomen, but he does not seek Erwin out. He has not eaten for almost a month, blood boiling and skin peeling away from his flesh as his human body rots. The meat on his bones burns and sizzles hideously, and he shrieks in pain and anguish at the torture. Erwin’s command on him had expired days ago, but Levi still refuses to go to him. He lets his body bear the burden of Erwin’s rejection, let’s the pain he suffers fuel his anger towards Erwin. So that when he finally returns, Erwin will learn to not punish him in such a way, and will be taught to not starve Levi like an unloved dog. Levi will etch into him his duty to satiate the demon’s hunger, his purpose to satisfy Levi. 

He allows Erwin three months of peace, the whole summer season, before he decides that Erwin’s playtime is up.

Levi finds him inside the library, alone, and drags Erwin from his armchair to the carpeted floor by his hair. The Commander scrambles to his feet but Levi knocks him back down onto his knees again.

“Levi!” Erwin shouts in protest, no doubt terrified of Levi’s appearance, which is beginning to fuse with his true form from the Realms, ugly and disturbing beyond human comprehension. But Levi pays him no heed, snarling and growling like a nasty beast, driven purely by his primal hunger and the carnal need to feed. He shreds Erwin’s trousers from his legs and leans in to nuzzle against the meat of Erwin’s inner thigh, where the skin is warmth and blood is plenty underneath. 

Erwin’s screams fill the library as Levi begins to eat, fangs piercing through flesh and into the plump veins beneath. There is nothing pleasant about the experience, no aphrodisiac effect like the mythology scripts like to proclaim, it is nothing but increasingly painful and dreadful. Erwin is soft against his other thigh, there is no pleasure to be derived from the act of Levi’s feeding. 

Levi keeps Erwin locked up in the library for a week, he doesn’t think Erwin deserves the luxury of a bed nor a bathroom. He forcefully feeds and replenishes conjured nutritions into Erwin by making him choke on his cock and swallowing his cum. Heals Erwin countless times so he can take more, over and over again. 

No one dares to interrupt Levi, not that the wards he’d set up against the library doors would allow them to anyway. 

After Levi’s finally feeling satisfied with Erwin’s punishment, he lets the Head Doctor of Royal Medicine into the library to tend to Erwin’s injured body. Hange takes in the sight of the numerous wounds littered across Erwin’s skin. Scratches, bites, bruises, anything Levi could inflict onto him with his own two hands, and curses Levi vehemently. She rushes to Erwin’s side and nearly cries when she realises that he’s barely conscious. Barely sentient. 

Levi has never met someone other than Erwin who can so fearlessly glare at him with such fierce emotion before. But there, he observes in Hange’s bright, brown eyes, is unadulterated hate, and for a second, he thinks Hange may be capable of expunging him back to his Realm, propelled by her wrath and despite.

He stares with disinterest from the height of Erwin’s armchair as Hange forces her fingers down Erwin’s throat to help him throw up and expel whatever substance Levi had pumped into his bloated stomach through his anus. He smirks gleefully when Hange tentatively tends to the wound between Erwin’s legs, her tender touch a perfect juxtaposition to the seething hate she sends his way, as it becomes increasingly apparent to her that the visceral injury Erwin had sustained had been due to Levi wanting to remove Erwin’s genitals but ultimately deciding against it halfway through. He had made sure that the damage he had caused to Erwin would not be permanent nor serious enough to be lasting. He will keep Erwin’s body pristine until the time is right.

However, Hange does not understand Levi’s intentions. Can only understand what she sees, displayed cruelly in front of her, the disfiguring wounds that mar Erwin’s body. Her fury only seems to grow exponentially as she treats Erwin’s twisted arm and mangled leg, both results of Levi’s uncontrollable urge to fuck his cock that much deeper into Erwin’s body.

“They were in the way,” he jesters at Hange, who remains uncharacteristically silent as she cleans and dresses Erwin’s wounds.

It takes three weeks before Erwin is well again, able to walk on his own two legs without the assistance of a cane or another person. The black and blue bruises are fading to an unsightly yellow, and his open cuts are now only pale marks decorating his skin. 

It takes three weeks before Hange tries to exorcise Levi, in order to save Erwin from his torture.

But she should have known, should have been aware that Levi is more powerful than any witch in the vicinity of the human realm. Levi rules dimensions where there are egregious monsters other demons don’t even know exist. Hange doesn’t know that Erwin has bound himself, his mind, body, and soul, to one of the most powerful beings of the existing boundaries, of the Unknown, and that is her mistake, her fallacy, her pathetic downfall. 

He does not touch a hair on her head, he does not even verbally threaten her, Erwin will not allow it. Instead, Levi punishes Hange for her foolishness by forcing her eyes open against her will, making her watch as he takes Erwin’s newly healed body apart. Makes her listen to Erwin’s incoherent shrieks and sobs, as Levi contorts his body and distorts his mind. Forces her to listen as Erwin deliriously screams and pleads for mercy like a newborn babe, and then wantonly begs Levi for more, more, _more_ , as Levi forcibly floods his system with sensations beyond human interpretation. Forces Hange to learn what will happen to the people she loves if she chooses to disobey him. 

Afterward, Levi tortures Hange by not allowing her to tend to Erwin’s wounds. Instead, he makes her instruct Erwin how to do it himself. She does so in a trembling voice, ashamed and self-loathing. 

It only takes a few days for Erwin to heal this time, however, she cannot bring herself to look Erwin in the eyes afterward, afraid and undeserving of the quiet kindness and forgiveness Erwin grants her in his tired blue eyes. 

They are not lifeless, though. Erwin still regards Levi with the same burning resentment blazing in his eyes. It sends licks of fire tingling across Levi’s skin. And their cycle carries on, Erwin abusing Levi’s power, and in exchange, Levi abuses Erwin’s body. 

Over time, Erwin learns to lean less on Levi’s strength, but this does not dissipate the pleasure Levi takes in when he has Erwin sprawled out beneath him, quivering like a newborn colt as he mindlessly whines for Levi’s touch, drunk on the endorphins the demon has dowsed his brain in. 

There is something peculiar about the way Erwin refuses to look at Levi the morning after, shame and humiliation burning bright across his face and chest, instead of the usual steely cold gaze. This, Levi blatantly realises, is Erwin beginning to blur the lines between what Levi is forcing him to take and what he actually, willfully, wants to take from Levi. This is Erwin finally giving into his humanity. And it is a beautiful occurrence that only Levi is privy to witness.

The thought leaves a near-fondness in Levi’s chest, and he watches and listens, perched on Erwin’s bed, as Erwin’s nightmares, haunted by Levi’s violence, start turning into quiet, fitful murmurs of his name. 

Erwin still kicks him out of his bed when the sun comes up. Erwin still struggles and fights him when the sun goes down. And Levi finds himself almost hesitant. If not for his misplaced affections for his contractor, which by no means is even close to any semblance of love, then it is for Erwin’s ability to withstand both pain and pleasure alike. There is a distinctive lack of resignation that Levi appreciates seeing in those icy blue eyes. 

That is, until the night of Her Royal Highness Historia’s coronation, Ymir pays Levi a visit. 

“His time has come,” she says in lieu of a greeting, “What are you going to make of his soul?”

“I will decide that later,” Levi answers in response, “What of yours?”

“She is still young,” Ymir delights, “But She has potential beyond Her age. I will let Her rule here before marking Her my queen. I will make Her a symbol of monarchy in my kingdom. It’ll bring order, strengthen the chain of command. Then I will breed Her, She will provide babes for me and all my Subjects.”

“You are too kind,” Levi snorts. 

“Oh?” She questions, amused, “Then what of you, my King? His term was due long ago, yet you have stayed with him for half his lifetime, carrying on at his bidding.” 

“He has grown on me,” Levi admits. Erwin’s blood mixes with his own in his veins, his tormented screeching is a constant, pleasant melody in Levi’s mind. He’s become attached to the way Erwin can still manage to glare at him with hate so fearlessly, he’s become entranced by the idea of breaking Erwin’s spirit after failing time and time again. He wants to ruin Erwin, utterly and entirely. Destroy him with absolution.

The solution is simple. He will just continue to do so after Erwin’s death in the human realm.

“I do not wish to see him waste away for eternity enticing filthy lowlives.” 

“Then it is not I who has become too kind my King, it is you who has become too soft.” Ymir laughs mirthlessly. “I must go now, Her Majesty is summoning me.”

When she leaves, Levi goes to seek out Erwin. 

He finds the Commander waiting for him in one the less visited back gardens of the castle. 

“Is this where you want your servants to find you?” Levi questions as he approaches, unhurried. They have all the time in the world.

Erwin shakes his head. “I must die away from the party. I have killed enough innocent men in this lifetime, I do not wish to condemn another to the same fate for the suspicion of my death.”

“Very well.” Levi pulls Erwin onto his lap and grips a strong wrist up to his lips, lapping at the soft skin on the inside of it. “I will lend you my power for your last command.”

“Will you tell me how you became like this?” Erwin asks, flinching when Levi’s fangs break the skin and blood quickly begins to trickle down the length of his arm. 

“Sooner or later,” Levi mumbles, “After all, we have eternity together.”

Erwin hums at that. “Then, will you enlighten me on what you plan on doing with me?”

“I will make you my pet, my lapdog. You will serve me only,” Levi says, snaking a hand down Erwin’s waist. “It is not every day that there is a man who has enough power and Magic to bound their soul to mine. You would not understand, the jealousy and envy that I feel whenever one of my Children brings another bound soul back while I sit on my throne, no man daring to summon me.”

“Of course,” Erwin sighs, relaxed.

“You are not afraid of death,” Levi states. 

“No,” Erwin easily replies, “I knew of my death the moment I decided to summon you. Besides, it is only my materialistic body that will crumble.” 

“You are leaving your family and friends behind, you will never see them again. You will want to flee from me, but you cannot. You will want to die, but you will not be able to,” Levi says, shifting to Erwin’s other wrist once the one is his hands has become limp. “You will be tortured by the knowledge that you died, unable to prevent Historia from following your path.”

“Perhaps I will see Her there, then,” Erwin says, “In the afterlife. In Hell.”

“It is not Hell, Hell does not exist,” Levi says as he strips Erwin of his trousers, “It will be my Realms. We are beings of Magic after all, not Fate.”

“The priests would cry outrage at such blasphemy.” Erwin grunts as Levi sticks a finger rudely up his ass. “Truth to be told, I have never believed in the existence of God.”

“You would be right to do so,” Levi grins, “Those are just shoddy excuses for Magic. Explanations to placate humans' fear of the Unknown.”

“What is the Unknown?” Erwin asks, like a curious child. Levi finds a sick kind of joy in the innocence of Erwin’s voice even as he begins to bounce Erwin on his cock like a dirty whore. 

“You will know once you wake up.” Levi kisses the moan out of Erwin’s slack mouth. “Now, you must sleep. You must die for me.”

“Goodbye, Levi,” Erwin says, one last time.

“Goodnight, Erwin.” Levi presses a chaste kiss to his forehead, lets Magic weave and seal their bond. He purrs possessively, low in his chest as he patiently waits for Erwin to open his eyes again. 

Only this time, they will be Incubi instead of human. 

**Author's Note:**

> i might expand this au a little bit (some worldbuilding? a sequel? a prequel? who knows), but probably not. i'm not particularly a great fan of writing romanticised violence. it leaves a bad taste in my mouth, felt like i had to rinse my mouth after finishing this one lmao. 
> 
> also want to explicitly clarify that levi and erwin do NOT love each other in this au. nope. literally zero feelings of romance or anything even remotely resembling goodwill is going on. zip. zilch. nada. nothing. i do not endorse this kind of dynamic in reality, and neither should you.


End file.
